Use this in the server script

/*******************************/
var rightNow = GlideDateTime();     // Get the current time
var morningStart = 4*60*60*1000;    // Set numeric value of 4 AM
var afternoonStart = 12*60*60*1000; // Set numeric value of 12 Noon
var eveningStart = 18*60*60*1000;   // Set numeric value of 6 PM which 18 in 24  hour format
var welcomeMessage = "";
if(rightNow.getLocalTime().getNumericValue() > morningStart && rightNow.getLocalTime().getNumericValue() < afternoonStart){
    data.greeting = "Good Morning, ";
} else if(rightNow.getLocalTime().getNumericValue() > afternoonStart && rightNow.getLocalTime().getNumericValue() < eveningStart){
    data.greeting = "Good Afternoon, ";
} else{
    data.greeting = "Good Evening, ";
}
/*******************************/
data.name = '';
var firstName = gs.getUser().getFirstName();
if (firstName != '' || firstName != null || firstName != undefined) {
    data.name = gs.getUser().getFirstName();
}
/*******************************/
var aisEnabled = $sp.isAISearchEnabled();

if (aisEnabled) {
    data.typeAheadSearch = $sp.getWidget('typeahead-search', options);
} else {
    data.typeAheadSearch = $sp.getWidget('typeahead-search', options.typeahead_search);
}
/*******************************/